Adolescents Background

"Within any 24-hour period in the life of a teenager, eating
may be a positive or a negative experience. It may involve a quick snack
or a grazing process. Eating for teens may be a group decision, an interaction,
or an independent endeavor. The experience can vary greatly from teen
to teen and for any one teen. Inter- and intravariability may be great.
Conversely, eating may be a consistent, uneventful pattern hour-to-hour
or day-to-day." Gail C. Frank, 1997 (219)

For this report, the adolescent age group includes children ages 13 to
18 years, although adolescence is often defined as encompassing from 11
through 21 years (251). During adolescence, children undergo profound
biological, emotional, social, and cognitive changes to reach adult maturity.
They experience the physical transformation into young adulthood and must
psychologically adjust to a new body that has changed in shape, size,
and physiological capacity. At the same time, adolescents are striving
to attain a unique identity and value system separate from parents and
other family members as well as personal independence, while still needing
financial and emotional support from family members.

Adolescent needs for energy and all nutrients significantly increase
to support the rapid rate of growth and development; as much as 50% of
adult ideal body weight is gained in adolescence (251). Although appetite
and food intake increase, the struggle for independence that characterizes
adolescent psychosocial development often leads to the development of
high-risk nutritional behaviors such as excessive dieting, meal skipping,
use of unconventional nutritional and non-nutritional supplements, adoption
of fad diets, and excessive alcohol consumption. The high prevalence of
overweight and obesity, eating disorders, adolescent pregnancy, and the
lack of consumption of five fruits and vegetables a day are among the
challenging nutritional issues facing adolescents in the United States
(219;251).

Exhibit 5.1 (in the School Age
Children section) highlights differences in dietary assessment methodological
issues between school age children and adolescents. A number of factors
contribute to the challenge of collecting valid dietary information from
teenagers.

Rapidly changing eating habits. The eating habits of adolescents
are not static; they fluctuate throughout adolescence in relation to
psychological and cognitive development and to growth and appetite changes.

Unstructured eating. Snacking and meal skipping are routine; "Grazing"
is commonplace and teens may have "sneals" and not just snacks
and meals (219).

Peer influence exceeds parental influence. Eating away from home
becomes prevalent, and fast-food accounts for 31% of food eaten away
from home (218);
only one-third of middle-class US 14 year olds eat dinner with their
family on most days (239).

Age related compliance. An overall trend toward an increase in energy
underreporting with increasing age has been documented with DLW (Doubly Labeled
Water) studies in adolescents (161).

High prevalence of restrained eating. The well documented high prevalence
of dissatisfaction of many normal weight adolescents with their weight
has implications for bias in dietary surveys; inclusion of measures
of dietary restraint and body image is important in this age group (161).

Overweight and obesity may lead to underreporting of intake. As with
obese adults, obese adolescents underreport intake significantly more
than their non-obese counterparts; up to 40% of energy intake in obese
adolescents may not be reported (195).

Dietary assessment probing, coding, and reporting formats designed
for adults do not adequately reflect the eating patterns of teens. Dietary
assessment methods should address the eating environments and patterns
of teens as well as capabilities and motivation at different stages
of adolescence (161;218;219).

Research in school settings is difficult. Increasing time pressures
on school curriculum limit time for recruitment and adequate explanation
of study forms and procedures; alternative approaches and locations
that appeal to young people are needed (218;252).